Adjustable spacer for feed rolls



APll 22, 1958 v. sALlAMoNAs 2,831,562

ADJUSTABLE SPACER FOR FEED ROLLS Filed Dec.'24, 1954 f afm:

A T TOR/VEV United safes Patent o ADJUSTABLE SPACER FOR FEED ROLLS Vytautas Saliamonas, East Underwood Corporation, ration of Delaware Application December 24, 1954, Serial No. 477,563 2 Claims. (Cl. 197-138) Hartford, Conn., assigner to New York, N. Y., a corpo- This invention relates to paper-feeding rolls used with the platens of typewriters and similar business machines, and more particularly to elements for spacing such feed rolls properly on their supporting shafts in machines ot' this character. For example, in typewriters, to guide and hold a sheet of paper as it passes around a platen, it has long been the practice to use sets of feed rolls rotatably mounted on shafts which are supported to extend parallel to the platen axis, the shafts and rolls being pressed resiliently toward the platen and the paper thereon. However, for the desired proper action, the feed rolls must not be permited to shift longitudinally with respect to the platen to any appreciable extent, even when the carriage of the typewriter (which carries the platen and feed rolls) is moved or stopped suddenly. By test, it has been found that the maximum permissible tolerance for endwise movement or play of a platen on a carriage and of a feed roll on a supporting shaft is around ten-thousandths of an inch.

In the past, various kinds of spacers have been proposed and used for maintaining the feed roll clearance or end play at a minimum, while allowing the necessary free rotation of the rolls with respect to their supporting shafts and other parts of the assembly. These known spacers are inconvenient and expensive to install and adjust, and in some cases can not be depended upon to maintain the desired dimensions throughout the useful life of a machine. Although it is desirable to increase the number of rolls on a feed roll supporting shaft in order to improve the paper feeding action, the shortcomings of former known spacers have made this increase in number of rolls an expensive and troublesome change, at least partly because of the smaller resulting space available between the rolls and because of other reduced working space in the machine near the feed rolls.

It is therefore an object of the present invention to provide an improved form of inexpensive longitudinally adjustable spacer for the feed rolls of a typewriter or the like, a spacer which can occupy a relatively small space between adjacent rolls or between a roll and another element on a supporting shaft. Another object is to provide a spacer of the character outlined above which may be adjusted easily in length after assembly in a machine, even though there is but limited space in which to use a tool for making the adjustment. A further object is to provide such spacers which are adjustable by using simple tools which are readily obtainable. These features promote convenience in installation and dependability in use and permit a larger number of feed rolls to be used without increasing manufacturing costs.

These objects are met by making the spacer out of tubular metallic stock, cut and formed so that there remain two tubular end sections integrally joined together by a pair of diametrically opposite bridges. These bridges are then bent outwardly, with a fold or V at their centers having a peak or apex extending radially away 2,831,562 Patented Apr. 22',l 1958 ICC of the folds in the bridges extend radially outwardly of the rest of the spacer body,

be used to change the effective by squeezing the folds in the sired degree.

Other objects and further details of that which is believed to be novel and included in this invention will be clear from the following description and claims, taken with the accompanying drawing, in which is illustrated an example of feed roll spacer embodying the present invention and incorporating the adjustable bridges.

In the drawing:

Figure l is a perspective'view of part of a platen and feed roll assembly on a typewriter carriage, with the improved spacers shown adjacent the feed rolls on the supporting shafts;

Figure 2 is a plan view of a portion of the feed roll assembly alone, broken away in part to show further details of the feed rolls and of the adjustable spacers of this invention;

Figure 3 is an enlarged longitudinal sectional view through a single feedl roll, mounted on its supporting shaft, together with a plain tubular spacer and an adjustable spacer of the present invention, and indicating how the adjustable spacer may be lengthened by the application of a single pair of small-nosed pliers thereto;

Figure 4 is an enlarged perspective view showing an exemplary adjustable spacer, and indicating how a single simple tool may be applied to shorten the effective length of the spacer, and

Figure 5 is a still further enlarged perspective view showing a preferred form of spacer element according to this invention.

In usual typewriter construction there is a platen 10 mounted on a platen shaft 11, suitably journalledinthe end plates 12 (only one shown) of a horizontally movable carriage. An end knob 13 may be used to rotate the platen manually in a fashion readily understood, and

simple plier-like tools may length of the spacers easily proper manner to any dethe usual line-spacing mechanisms (n'ot shown) may also The supporting shafts extend axially parallel to the pla't'en` shaft, and are suitably biased for movement in a direction so that the surfaces of the feed rolls in each set can releasably engage the surface of the platen, or rather, engage a sheet of paper introduced between and the platen.

There are several ways to mount the feed roll shafts, 'y

but in the exemplary machine shown here, there is provided a tie rod 1S extending between the end plates of the carriage, a series of spaced feed roll support arms 19 pivotally mounted on the tie rod to support shaft 16, and an oppositely disposed series ofspaced feed roll support arms 2l pivotally mounted to support shaft 17.'v

The .support arms 19 and 21 are resilientlyV biased to move the shafts 16 and l? and the sets of feedjrolls 14 and 15 toward the platen by any suitable means, such as the springs 22 and Z3, which may be mounted elsewherein the carriage structure.

the feed rolls,

In order to retract the feed rolls from the platen for the easy introduction or adjustment of a sheet of paper between these elements, extensions 24 are provided on the feed roll support arms i9 and 2. These extensions bear against a rotatable shaft 2S having flat portions 26 opposite the extensions, so that when the shaft 25 is turned in its mountings as by the usual crank 27, link 28 and pivoted release lever 29, the extensions will ride out of the flat portions 26 and onto the periphery of the shaft 25. This rocks the feed roll support 'arms 19 and 21 in directions away from the platen, yagainst the bias of the springs 22 and 23.

VThe support arms 19 and 21 may engage the feed roll supporting shafts 16 and 17 by means of hooked ends 31, and 32 on the arms. These hooks receive and support the shafts between pairs of the feed rolls i4 and 15 and also near the ends of each of the shafts. This multiple support of each shaft is advantageous because the pressure of each feed roll on the platen can beadjusted independently of the other feed rolls, and sagging of the centers of the feed roll supporting shafts can be prevented. However, as pointed out above, it is desirable to have as many feed rolls as possible mounted on a single supporting shaft, and the use of a large number of supporting arms for the shaft decreases the space available for the feed rolls and for necessary feed roll spacing elements. By using the spacers of the present invention, it is possible to maintain a maximum number of feed rolls and of supporting arms on a feed roll supporting shaft of a given length, while facilitating the elimination of end play of the rolls on the shaft.

Elimination of end play may be accomplished alone by the use o-f adjustable spacers according to this invention, or, as shown in the drawing, by the use of standard or conventional spacers in conjunction with the improved adjustable spacers. Referring particularly to Figures 2 and 3, a feed roll is slipped onto a supporting shaft, and at each end of the roll a spacer is provided, in the case shown, a plain tubular spacer 33 at one end and an adjustable spacer 34 at the other end. These spacers hold the ends of the feed rolls away from the hooks 31 and 32 where they engage the shafts 16 and 17 Ibetween the spacers and at the ends of the shafts. To prevent endwise movement of the shafts in the hooks of the support arms, the ends of each shaft may be provided with circumferential grooves 35 in which snap-lock rings 36 will seat.

Due to manufacturing variations, which are multiplied as the number of parts are increased, it is virtually impossible to fabricate and assemble a set of feed rolls, spacers and supporting arms on a single supporting shaft while keeping the accurate dimensions required to prevent end play of the feed rolls on the shaft. Therefore, according to this invention, an attempt is made initially only to approximate the desired dimensions, and final perfection in fitting is obtained by shortening or lengthening the adjustable spacers on each supporting bar after assembly. Wherever ordinary spacers are used, these may be of any desired form, but the character of the adjustable spacers is important because these perform the entire function of increasing or decreasing the space on the supporting shaft for the feed rolls, whereby the rolls are neither so tight as to bind noir so loose as to have undesired end-play.

Each adjustable spacer 34 is made from seamless cylindrical tubular metallic stock. For a typical machine it has been found satisfactory to use as spacer stock, cold drawn seamless brass tubing, .187 in. outside diameter and .143 in. inside diameter, leaving a wall thickness of from .02 to .024 in. when working with tolerances of plus or minus .002 in. This material is rigid enough so that it will not bend or become accidentally deformed during ordinary handling or with usual service in a typewriter. On the other hand, this thickness of tubing is exible enough so that it may be bent by using hand tools. It is purposely selected to be non-resilient, i. e. so that it will not spring back to any observable degree after being bent. For lack of a more 'accurate expression the word deformable will be used to denote the characteristic of liexibility without resilience.

The tubular stock is cut into any desired lengths, and each length is then milled, ground or otherwise cut to remove most of the material from the central portion at two sectors or segments 37 opposite each other, leaving two similar diametrically opposed, relatively narrow, integral bridge portions 38, joining tWo similar tubular end sections or collars 39. The bridges are at this point in a straight state, extending directly from end section to end section in the plane of the original tube.

Next, the bridges are bent or upset at their centers, in a direction radially outward of the original tube, and a partly closed fold or V 41, is thereby formed in each bridge, having a central peak or apex as at 42. See Figure 5 for the preferred form of the completed adjustable spacer. The end sections are of course coaxial, or arranged on the same axis with each other.

After the feed rolls and spacers have been slipped onto a supporting shaft, the snap rings may be put into place at the shaft ends, and the shaft placed in the hooks of the supporting arms which carry the assembly. In the assembly shown, a hook will engage the shaft at each end, next to a .snap ring, and hooks Will also engage the shaft between the two spacers which separate each feed roll from the next one. Since the spaces between the hooks are relatively fixed, at least one of the spacing elements on either side of each roll should be of the adjustable type.

if a particular feed roll has more than the desired minimum end play when first mounted as described above, then a pair of small-nosed pliers or similar tool may be applied against the peaks of the folds of an adjustable spacer on that section of the supporting shaft, as shown by the dotted lines 43 on the right hand end of Figure 3. An inward radial squeeze applied by the pliers will tend to straighten out or open the folds simultaneously, and spread the end sections of the spacer until the slack space is eliminated. Conversely, if the feed roll is too tight, a tool such as split or forked nose pliers 44 may be applied to the bends of the spacer as shown by the dot-dash lines in Figure 4, and sufficient inward pressure exerted in an axial direction on the sides of the V- bends to close or atten the folds simultaneously until the roll is free for rotation. If the rolls should become loose as a result of prolonged or severe use of the machine or springing of the parts, they may be easily tightened again by using a pair of pliers on the adjustable spacers as described in connection with Figure 3. Because the bridges of the spacers are both bent equally and simultaneously, the end sections will remain in coaxial alignment regardless of the adjusted length of the spacer.

Note that even though there is but a small space available betweenl the adjustable spacers and other elements on the supporting shaft, there is ample room to manipulate the pliers to adjust the spacerlengths, Furthermore, even though other portions of the typewriter may be located closely adjacent the feed roll sets when lthe entire machine is assembled, the plier-like tools can still be used to adjust the spacers as long as the spacers are accessible or open from at least one lside. This is so because the peaks of the folds extend outside the outer cylindrical surfaces of the mbular end sections.

Seamless metallic tubing is preferred as the stock for the spacers because it has little tendency to collapse or .get out-of-round when worked, and furthermore it can present a smooth continuous bearing surface at its ends where it may touch the rotable feed rolls or other parts. For best results, the adjustable spacers should not bind on the supporting shafts nor interfere in any way with rotation of the feed rolls, no matter what the position of adjustment of the spacers. Seamless cylindrical tubing insures this result.

As will be evident from the foregoing description, certain aspects of this invention are not limited to the particular details set forth as an example, and it is contemplated that various and other modifications and applications of the invention will occur to those skilled in the art. It is therefore intended that the appended claims shall cover such modifications and applications as do not depart from the true spirit and scope of the invention.

What is claimed as new and is desired to be secured by Letters Patent of the United States is:

1. For use on a typewriter feed roll supporting shaft located in a limited space, a device for maintaining feed rolls and other elements at spaced distances from each other on said shaft, said device being adjustable in length entirely by the use of plier-like tools manipulated within said limited space outside of said shaft, said device comprising a single generally tubular seamless deformable body slidable on said shaft, two coaxially arranged end sections on said body spaced from each other along said shaft, and a pair of opposed bridge portions spanning the space between and integral with said end sections on either side of said shaft, each of said bridge portions being bent from end to end in a fold with the peak of the fold extending radially outward of said end sections and said shaft, and with the ends of the sides of the fold joined to said sections, whereby simultaneous compression of the peaks toward the shaft by a tool will spread the sides of the folds and lengthen the body, and pressing the sides of the folds toward each other by a tool applied outside of the folds will close the folds and shorten the body in an axial direction.

2. For use on a feed rool'supporting shaft located within a limited space on a typewriter carriage, a tubular element for maintaining feed rolls and other elements in spaced relation on said shaft, said tubular element being longitudinally adjustable by the use of pinching tools manipulated entirely within said limited space outside of said supporting shaft, said element comprising two similar cylindrical tubular end sections axially aligned with but spaced apart from each other on said shaft, and a pair of relatively narrow similar deformable metal bridge portions diametrically opposite each other on said shaft, each bridge portion being joined at one end to one of said end sections and at the other end to the other of said end sections, each bridge portion having a partially closed fold therein with a peak extending radially of the common axis of said end sections outwardly of said shaft beyond the outer cylindrical surfaces of said sections, whereby a tool may be used within said limited space to pinch and further close said folds thereby shortening the span of said bridge portions and the length of said tubular element, and alternatively a tool may be used to pinch and compress the peaks of said folds toward said shaft to spread and further open said folds thereby increasing the span of said bridge portions and the length of said tubular element.

References Cited in the ile of this patent UNITED STATES PATENTS 

